Vanishing Fe 3d orbital moments in single-crystalline magnetite

We show detailed magnetic absorption spectroscopy results of an in situ cleaved high quality single crystal of magnetite. In addition the experimental setup was carefully optimized to reduce drift, self absorption, and offset phenomena as far as possible. In strong contradiction to recently published data, our observed orbital moments are nearly vanishing and the spin moments are quite close to the integer values proposed by theory. This very important issue supports the half metallic full spin polarized picture of magnetite.Comment: 7 pages, 4 figure

The interstellar oxygen-K absorption edge as observed by XMM-Newton

High resolution X-ray spectra of the Reflection Grating Spectrometer (RGS) on board the XMM satellite are used to resolve the oxygen K absorption edge. By combining spectra of low and high extinction sources, the observed absorption edge can be split in the true interstellar (ISM) extinction and the instrumental absorption. The detailed ISM edge structure closely follows the edge structure of neutral oxygen as derived by theoretical R-matrix calculations. However, the position of the theoretical edge requires a wavelength shift. In addition the detailed instrumental RGS absorption edge structure is presented. All results are verified by comparing to a subset of Chandra LETG-HRC observations.Comment: LaTeX2e A&A style, 10 pages, 12 postscript figures, accepted for publication in Astronomy and Astrophysic

Simulating Superior Genotypes for Plant Height based on QTLs: Towards Virtual Breeding of Rice

Crop plant researchers and agronomists have in the recent past increasingly turned to crop modeling as a promising tool for the integration and exploration of experimental data from breeding and agronomy. Set up suitably, crop modeling can then also be used to predict performance of future high-yielding cultivars, e. g. of rice, which is one of the major food crops worldwide. Questions such as "Which combination of alleles is likely to have the strongest influence on the development of the individual phenotype?" or "In which way is QTL action modified by a particular environment?" can be tackled with the help of a crop modeling approach. As a further extension of a previously established Functional-Structural Plant model (FSPM) of rice we present here simulated "virtual" reproduction of individuals using QTL information, which can contribute to providing answers to these difficult questions. In this study, we briefly describe the way QTL information has been integrated into the rice model, and sketch the algorithmic implementation of processes leading to the creation of filial genotypes from parental genotypes via simulated sexual reproduction. The phenotype value, which in this case was plant height, was determined with the rules that specify the genetic processes operating on genotypes as intrinsic properties of each individual. The mapping results from the simulated population were compared with the input values for the parental lines. It is shown that the rice model faithfully reflected the genetic properties from the parental lines with low bias, which suggests a reasonable way to integrate QTLs into the plant eco-physiological model with the predictive properties. It could in the future be used as a supporting tool in breeding practice

LET spectra measurements of charged particles in the P0006 experiment on LDEF

Measurements are under way of the charged particle radiation environment of the Long Duration Exposure Facility (LDEF) satellite using stacks of plastic nuclear track detectors (PNTD's) placed in different locations of the satellite. In the initial work the charge, energy, and linear energy transfer (LET) spectra of charged particles were measured with CR-39 double layer PNTD's located on the west side of the satellite (Experiment P0006). Primary and secondary stopping heavy ions were measured separately from the more energetic particles. Both trapped and galactic cosmic ray (GCR) particles are included, with the latter component being dominated by relativistic iron particles. The results from the P0006 experiment will be compared with similar measurements in other locations on LDEF with different orientation and shielding conditions. The remarkably detailed investigation of the charged particle radiation environment of the LDEF satellite will lead to a better understanding of the radiation environment of the Space Station Freedom. It will enable more accurate prediction of single event upsets (SEU's) in microelectronics and, especially, more accurate assessment of the risk - contributed by different components of the radiation field (GCR's, trapped protons, secondaries and heavy recoils, etc.) - to the health and safety of crew members

Hot dense capsule implosion cores produced by z-pinch dynamic hohlraum radiation

Hot dense capsule implosions driven by z-pinch x-rays have been measured for the first time. A ~220 eV dynamic hohlraum imploded 1.7-2.1 mm diameter gas-filled CH capsules which absorbed up to ~20 kJ of x-rays. Argon tracer atom spectra were used to measure the Te~ 1keV electron temperature and the ne ~ 1-4 x10^23 cm-3 electron density. Spectra from multiple directions provide core symmetry estimates. Computer simulations agree well with the peak compression values of Te, ne, and symmetry, indicating reasonable understanding of the hohlraum and implosion physics.Comment: submitted to Phys. Rev. Let

Playing dice with mice: building experimental futures in Singapore

This is a postprint of an article published in New Genetics and Society, 2011, Vol. 30, Issue 4 pp. 433 – 441 © 2011 copyright Taylor & Francis. New Genetics and Society is available online at: http://www.tandfonline.com/loi/cngs20#.UqsI0tJdU24This short paper adds to debates on the unfolding spaces and logics of biotechnological development bought together in the 2009 special issue of New Genetics and Society on ‘Biopolitics in Asia’. Though an unlikely comparison between the development of the genomic sciences and the building of gambling casinos in the city state of Singapore, it reflects on the nature of political and technological investments in this South-East Asian city. It argues that Western expectations of a link between scientific practices, and civic epistemologies linked to democratic decision-making, are replaced by a rather different future orientation to scientific experimentation, economic investment and social development in Singapore

Plasminogen activator‐1 overexpression decreases experimental postthrombotic vein wall fibrosis by a non‐vitronectin‐dependent mechanism

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108289/1/jth12644.pd